How old is the oldest volcanoes

Volcanoes of the World, v. Venzke, E ed. Smithsonian Institution. Downloaded 14 Nov What volcanoes have had the longest eruptions? The Island of Hawaii has two active volcanoes, Kilauea and Mauna Loa, which have been active for at least , years. Hawaii is the youngest of a long line of volcanoes called the Hawaiian-Emperor Sea Mount chain. The oldest volcano in the chain is the inactive volcano Meiji, which is 85 million years old.

So to answer your original question, volcanoes have been erupting on Earth for at least the last 4 billion years and were undoubtedly more active in the distant past than they are today. During historic times, not a year has gone by without a volcanic eruption somewhere on Earth. Volcanoes are really mountains that build taller and taller, with time, as they erupt.

That means that molten rock, magma, comes from within the earth and erupts onto the surface. The volcano might be explosive and produce ashes or be effusive and produce lava.

The explosions are usually first because there are lots of gases inside the magma. When you have a bottle of soda pop, you do not see any bubbles of gas, but when you open it, bubbles form almost instantly.

Once the gas bubbles have all escaped, the soda is flat. Once the magma is flat, a lava flow comes out. Most of the volcanoes from around the Pacific Ocean are composite, which means that there are layers of ashes and lava.

Most volcanoes are 10, to , years old — it takes time for them to grow big. What gases do volcanoes emit? Inside the crater of a volcano there is nothing alive and many small fumaroles holes release nasty gases.

There are many colorful minerals being deposited from the gases as they cool. The most important gas is water, and then carbon dioxide. These two important gases are not poisonous. Sulfur dioxide, hydrogen chloride, and hydrogen fluoride are emitted, as well. They are strong poisons and cause pollution problems. What kinds of rocks do volcanoes make? Volcanoes make many different types of rocks. For example, black shiny rocks with only a few crystals are usually basalt.

The opposite — white shiny rock with many crystals and often many bubble holes inside the rock is rhyolite. In between are andesites, which are light gray and usually have large box-shaped crystals called plagioclase. They come from the Andes Mountains, which is a chain of volcanoes in South America. The Hawaiian islands are mostly made up of basalts, so they are famous for their beautiful black-sand beaches.

How many volcanoes have been identified in the world? We know of at least 1, active volcanoes around the world. In the continental United States, the most recent and deadly volcanic eruption came on May 18, , when Mt. Helens blew its top—and one whole side of the mountain—killing 60 people and leveling square kilometers sq.

The most powerful volcanic eruption observed in recent history was in at the Tambora volcano in Indonesia, which produced huge pyroclastic flows and ejected large quantities of fine ash and gases into the stratosphere. The eruption killed an estimated 60, people and the resulting volcanic cloud lowered temperatures around the globe by as much as 3 degrees Celsius 5.

Volcanic eruptions are vivid reminders that our planet is a geologically active and dynamic place. On any given day, scientists estimate 20 volcanoes worldwide are erupting on the land.

Still more are probably erupting underwater, but scientists don't have enough instruments to detect them. Many of these submarine eruptions theoretically occur along mid-ocean ridges, where an estimated 80 percent of Earth's magma erupts unnoticed.

An erupting volcano is like a window into the depths of the Earth, because lava and other erupted material provide clues to the mystery of what is going on far below the surface. The machine compresses and melts rock samples, essentially recreating the magma from which the rock sample came. She uses her findings to understand how the interior of the planet has evolved over many millions of years.

Benjamin Andrews, another Smithsonian volcanologist, performs similar experiments on erupted volcanic rocks in order to understand the geological conditions deep underground that preceded the eruptions.